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Visar resultat 6 - 10 av 192 avhandlingar som matchar ovanstående sökkriterier.

1. 6. Large eddy simulation of combustion using linear-eddy subgrid modeling

   Författare :Salman Arshad; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES-LEM; splicing; turbulent combustion; super-grid LES-LEM; CFD; linear eddy model; reaction-rate closure; large eddy simulation;

   Sammanfattning : As emissions regulations are getting stricter and efficiency requirements of internal combustion engines (ICE) are increasing, different concepts to improve combustion are being investigated. For example lean stratified premixed combustion, homogeneous charge compression ignition (HCCI), use of more exhaust gas recirculation (EGR) to reduce NOx etc. LÄS MER

3. 7. Acoustical Measurements of Material Nonlinearity and Nonequilibrium Recovery

   Författare :Kristian Haller; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear acoustics; nondestructive testing; activation density; slow dynamics; nonequilibrium recovery; resonance frequency; nonlinear wave modulation spectroscopy; harmonic generation; trapped modes; open resonator; sweep rate; constant strain sweep;

   Sammanfattning : A damaged material or a material with non perfect atomic geometry, dislocations or cracks, exhibits two types of characteristic responses to acoustic excitations. First is the fast nonlinear dynamics response that is present as long as the material is excited. As soon as the excitation stops the response disappear. LÄS MER

4. 8. Assessment of Experimental, Computational, and Combined EFD/CFD Methods for Ship Performance Prediction

   Författare :Kadir Burak Korkmaz; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; numerical friction line; form factor; CFD; measurement uncertainty; power prediction; EFD; verification and validation; Combined CFD EFD Methods;

   Sammanfattning : In today’s highly competitive market, alongside increasingly stringent regulatory requirements, the precise prediction of ship performance has assumed paramount importance for both design verification and operational evaluations. This thesis addresses the need for a comprehensive assessment of Experimental Fluid Dynamics (EFD), Computational Fluid Dynamics (CFD), and their combination to enhance the accuracy of performance predictions. LÄS MER

5. 9. Squeak and Rattle Prediction for Robust Product Development in the automotive industry

   Författare :Mohsen Bayani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; structural dynamics; finite element analysis; product development; squeak and rattle; sound quality; simulation;

   Sammanfattning : Squeak and rattle are nonstationary, irregular, and impulsive sounds that are audible inside the car cabin. For decades, customer complaints about squeak and rattle have been, and still are, among the top quality issues in the automotive industry. LÄS MER

7. 10. Simulations of compressible flows associatedwith internal combustion engines

   Författare :Olle Bodin; Laszlo Fuchs; Mihai Mihaescu; Michael Leschziner; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LES; Gas exhange; exhaust port; exhaust manifold; POD; DMD; exhaust; LES; Gasväxling; avgasport; avgasgrenrör; POD; DMD;

   Sammanfattning : Vehicles with internal combustion (IC) engines fueled by hydrocarbon compoundshave been used for more than 100 years for ground transportation.During these years and in particular the last decade, the environmental aspectsof IC engines have become a major political and research topic. LÄS MER